A rocky Irish outcropping with a history of wealth, conflict, and ruin.

This European portal tomb has a capstone that weighs around 150 tons.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

The oldest inn in Kilkenny was established by the first convicted witch in Ireland.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

These imposing walls and towers look more like the ruins of a fortress than a monastery.

Huge standing stones mark a site of megalithic mystery.

The ruins of a medieval monastery named after a type of tree.

A gated cross stands on the site where an Irish revolutionary met his end.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

This single room has survived the centuries with almost no deterioration.

Ireland's most remarkable collection of these curious cone-shaped houses is worth the buzz.

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

Ruins battered by centuries of war and disaster offer a wondrous glimpse of medieval Ireland.

A moody and picturesque riverside ruin overgrown with vegetation.

Achill's most recently abandoned village dates back to to the Age of Enlightenment.

A giant roll of mints marks the birthplace of one of America's most famous candy brands.

A standing relief of a Norman knight whose posture marks him as a Crusader.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

The purported world's shortest international bridge connects a homeowner in Canada to his backyard in New York.

This stone tower marks a lookout point over the historic Washington Crossing, and maybe some buried treasure.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

Mysterious rocks that ring musically when struck.

A winding, cliffside stretch of road overlooking the Delaware River.